The present invention relates to a charged particle beam control element for controlling a trajectory or a cross-sectional shape of a charged particle beam by an electrostatic field, a method of fabricating the charged particle beam control element, and a charged particle beam apparatus.
The conventionally well-known charged particle beam control elements for controlling the trajectory or the cross-sectional shape of the charged particle beam by the electrostatic field include electrostatic deflectors, electrostatic lenses, stigmators, and so on.
FIG. 11 is a top plan view to show a conventional electrostatic deflector 100. FIG. 12A is a figure to show an A—A cross section of FIG. 11 and FIG. 12B a figure to show a B—B cross section of FIG. 11.
The electrostatic deflector 100 has octupole metal electrodes 101 (see FIG. 11). Each of the metal electrodes 101 is fixed to the inside of an insulating sheath 102 with fixing screws 103, 104 (see FIG. 12A). A voltage-applying wire 105 to each metal electrode 101 is directly fixed to the corresponding metal electrode 101 with a wiring screw 106 (see FIG. 12B).
In this electrostatic deflector 100, an electrostatic field is established according to voltages applied to the respective metal electrodes 101 inside a space 107 surrounded by internal surfaces 101a of the respective metal electrodes 101. Accordingly, the charged particle beam passing along the center axis Z in the space 107 is deflected according to the electrostatic field established in the space 107.
Each of clearances 108 between adjacent metal electrodes 101 is not of the shape of a straight line, but of the shape bent twice and then reaching the insulating sheath 102. This is for the purpose of keeping exposed portions 109 of the insulating sheath 102 off direct view from the charged particle beam passing the space 107. This structure prevents charge-up of the insulating sheath 102 and allows the electrostatic field in the space 107 to be precisely controlled by the voltages applied to the respective metal electrodes 101.